Acral pseudolymphomatous angiokeratoma of children in an elderly man: report of a case and review of the literature.

Acral pseudolymphomatous angiokeratoma of children (APACHE) is clinically characterized by angiomatous papules that preferentially affect acral areas of children. It is currently believed to be a variant of pseudolymphoma rather than angiokeratoma. Histopathologically, a mixed inflammatory cell infiltrate comprising B- and T-lymphocytes and a proliferation of thick-walled blood vessels are the hallmark. In the literature, although more adult cases are being described, the clinical, epidemiologic and histopathologic data of this presentation is scant. We report a 76-year-old man who presented with a 5-year history of progressively increasing asymptomatic dusky dome-shaped papules and plaques on his upper and lower extremities. Histology was consistent with APACHE. After reviewing all the adult cases in the literature and comparing them to the classical variant in children, we found no significant difference warranting separating these two variants. We prefer the designation "papular angiolymphoid hyperplasia" to APACHE as it encompasses all the childhood and adult cases involving acral and nonacral sites and highlights the histological and sometimes clinical similarities this entity shares with angiolymphoid hyperplasia with eosinophilia.

Atrophoderma of Pasini and Pierini: a clinical and histopathological study.

BACKGROUND: Idiopathic atrophoderma of Pasini and Pierini (IAPP) usually manifests as one or multiple depressed and hyperpigmented patches, with a predilection to the trunk. No diagnostic changes are usually seen on histology. Elastic stains often reveal no abnormalities. OBJECTIVE: To review our cases of IAPP, describe their clinical and histological findings and compare them with the literature. METHODS: Retrospective review of IAPP cases who presented to our institution between 1994 and 2006. RESULTS: From a total of 16 patients, only 19% displayed hyperpigmented lesions, while 81% had either hypopigmented (9/16) or skin-colored (4/16) lesions. The sites predominantly affected were the lower extremities (62.5%), followed by the upper extremities and trunk. Only in one patient was IAPP co-existent with morphea. Histology revealed no diagnostic abnormalities; however, elastic stains showed a spectrum of changes ranging from normal to severe diminution and fragmentation of elastic fiber network. CONCLUSIONS: Our study shows several new aspects of IAPP. Clinically, the lesions were most commonly hypopigmented and involved predominantly the extremities. Histologically, IAPP exhibited a spectrum of alterations in elastic fibers. The most prevalent form of IAPP in our country seems to be unassociated with morphea.

Streptococcus sp. and Staphylococcus aureus isolates from patients with psoriasis possess genes that code for toxins (superantigens): clinical and therapeutic implications.

Superantigens are powerful T lymphocyte-stimulating agents that are believed to contribute to the pathogenesis of certain diseases such as psoriasis. Toxins produced by Streptococcus pyogenes and Staphylococcus aureus are superantigens. The aim of this study was to detect genes that code for superantigens in Streptococcus and Staphylococcus aureus isolates from psoriatic patients. Primers to amplify streptococcal pyrogenic exotoxin A, B, and C and streptolysin O genes and staphylococcal enterotoxin A, B, C, and D genes were used. Streptococcal exotoxin B was detected in five streptococcal isolates. Staphyloccocus aureus enterotoxin A and/or C genes were detected in nine S. aureus isolates. Isolates from 13 of 22 patients possesed gene(s) that code for toxin(s) (superantigens). These results might support the role of superantigens in the exacerbation of psoriasis.

HLA allele associations and V-beta T-lymphocyte expansions in patients with psoriasis, harboring toxin-producing Staphylococcus aureus.

HLA alleles have been associated with psoriasis. Toxin-producing strains of Staphylococcus aureus behave as superantigens, and if present in patients, might play a role in the exacerbation of psoriatic lesions by activating certain V-beta (V beta) T-lymphocyte subsets. Allele frequencies in 22 patients and 22 controls (alleles determined by DNA/SSP typing) were used to calculate a relative risk of $4.7$ ($P < .05$) for HLA-Cw6. S aureus was isolated from the throat of 11 patients. Enterotoxins A and C were detected by agglutination in the culture filtrate of one isolate. The enterotoxin A and/or C genes were detected by PCR in 9 isolates, and transcripts were detected by RT-PCR in 7 of them. None of the isolates from controls harbored enterotoxin genes. V beta expansions were detected by RT-PCR in all 22 patients. Low or no V beta expansions were obtained in controls. The association of HLA-Cw6 with psoriasis in Lebanese concurs with that reported for other ethnic groups. Toxin-producing isolates that colonize patients might play a role in the exacerbation of psoriatic lesions.